I don't fully agree with this part. Yes, Patrick Stewart did want Picard to become an action hero. However, the entire thrust of First Contact's story was about how Picard still had some form of PTSD from his experience with the Borg and how that fundamentally was still haunting him. And let's be honest. Picard showed in TNG that he could hold his own in a fight when he needed to. But the fact is, Starfleet was actually right in their reasoning at the beginning of the film. I don't feel like the "action hero" moments that Picard has in this film feel tacked on in any way. It is when it continues beyond that film that it becomes obviously just a re-working of the character.
I respect your interpretation of Picard's actions, and if it had been contained to just this movie, then I might agree with you. But knowing the studio's (and Stewart's) want to turn Picard into an action hero, and the next two films essentially going down that road, makes me suspect that any "Borg PTSD" that Picard might have had was just the excuse the writers needed to make that happen. Remember that Picard is just a fictional character subject to the whims of whoever is writing him (and Stewart's demands.)
I agree, except I think this goes all the way back to "The Best of Both Worlds." I have always said that I think "Q Who?" was really the only time they got the Borg right, because that was written by Maurice Hurley who created them. By BoBW, they were already struggling with the idea of the Borg not having a leader. So first we get Locutus, then we get Hugh, then we get Lore, then we get the queen. The writers were always trying to take the Borg and turn them into a traditional villain with a leader instead of one collective mind.
(Of course, all that pales in comparison to how they become neutered in Voyager, but that's a discussion for another day.)
You make some good points (although making Hugh a 'Borg leader' is a bit of a stretch.) I agree that "Q Who?" was the best interpretation of them, and the only one that showed the Borg as an independent species of humanoids who willingly chose to become cybernetically enhanced, rather than the later retcon of them being assimilated against their will from other species. And honestly, the Locutus thing wasn't really so much about the Borg wanting a 'leader' so much as it was just for the shock value of Picard being turned into a Borg and challenging Riker. Because the Borg absolutely did not need someone to speak for them. That was just a plot contrivance for drama's sake (and it did work effectively, but that's all that it was; it was not a logical thing for the Borg to have done other than get Picard's knowledge of Starfleet's defenses. After that he was pretty much no different than the other drones.)